In George Orwell's novel 1984 the ruling Party is creating a "new version" of English, called Newspeak, which focuses on removing any and all parts of the language which can be used to express any opinion, idea or concept which the Party does not agree with. The purpose of Newspeak is to counter rebellion, and is based on the idea that "if you cannot put it into words, you cannot contemplate it".
I'm wondering if this would actually be the case in real life. Would a human who does not have the language capabilities to express/describe the idea of "I don't like the goverment, something should be done against it" also be unable to truly work out/understand that idea itself within their own head?